学步园

class Base<br /> {<br /> public:<br /> virtual bool operator == (int iValue)<br /> {<br /> std::cout << "I am Base class !" << std::endl;<br /> return true;<br /> }<br /> virtual ~Base(){}<br /> };<br /> class Derive: public Base<br /> {<br /> public:<br /> virtual bool operator == (int iValue)<br /> {<br /> std::cout << "I am Derive class !" << std::endl;<br /> return true;<br /> }<br /> virtual ~Derive(){}<br /> };<br /> int main()<br /> {<br /> Derive derive;<br /> Base* pBase = &derive;<br /> Derive* pDerive = &derive;<br /> *pBase == 0;<br /> *pDerive == 0;<br /> return 0;<br /> }

应该注意父类指针实际指向的是子类对象时，在调用虚函数时就会发生多态。